Ticks, mosquitoes on the rise in Iowa

New report warns of climate impact on wildlife

DES MOINES — Ballooning amounts of ticks, mosquitoes and poison ivy are invading Iowa because of climate change, and the increase will bring higher rates for disease, according to a report by the Iowa Wildlife Federation.

“If we keep the status quo the way we’re living, it will keep getting worse and we will start seeing diseases we never dreamed about coming to our soil,” said Dr. Yogesh Shah, associate dean of the Department of Global Health at Des Moines University.

To illustrate his point, Shah highlighted the rise of Chikungunya, a viral disease transmitted by mosquito bites, which starts with cold-like symptoms and then persists as joint pains for up to several years. Chikungunya, he said, was hardly discussed just six months ago, but will likely become more prevalent.

Shah said that with every degree increase in temperature, mosquito population increases by nearly tenfold — plus the viruses are living longer in each mosquito.

The report found that more carbon dioxide in the atmosphere, mainly from burning fossil fuels, is causing poison ivy to grow more rapidly and with stronger toxicity.

“If a drop used to cause a rash, now it’s just half a drop,” Shah said.

Deer ticks that carry Lyme disease are expected to be “more widespread than ever before” because of milder winters.

“Climate change is not so subtle anymore,” said Joe Wilkinson, president of the Iowa Wildlife Federation. “With temperatures going up a degree to two, as a human, I can handle that. But what will be the cumulative effect?”

There will be more itching, sneezing, swelling and gasping for breath as Pennsylvania’s climate shifts and residents are exposed to more poison ivy, stinging insects, pollen allergies and lyme-disease-bearing ticks, and experience increased asthma, respiratory disease and heat-related deaths.

That was the assessment of scientists and physicians at a one-day climate change conference sponsored by the Allegheny County Health Department and the University of Pittsburgh’s Graduate School of Public Health last week.

They said a silver lining is that Pennsylvanians won’t see the worst of those negative impacts until after 2050. But the bad news, echoing the findings contained in the third U.S. National Climate Assessment released May 6, is that the changes already have begun.

And, they agreed, the negative consequences of climate change brought on by man-made emissions of greenhouse gases will worsen the longer the world waits to reduce those emissions.

Raymond Najjar, a professor of oceanography in the Meteorology Department at Penn State University and an author of the 2009 Pennsylvania Climate Impact Assessment, said the most recent assessment released three weeks ago shows “some climate change is unavoidable,” and the state will get warmer and wetter. Heavy downpours will be more intense and more frequent.

He predicted that unless Pennsylvania cuts its emissions of greenhouse gases — including nitrogen oxides, carbon dioxide, sulfur dioxide and volatile organic compounds — to 20 percent of what they are now, the state’s summer heat index will become 8 to 10 degrees warmer by the end of this century.

Without that level of emissions cuts, the number of days the temperature tops 90 degrees Fahrenheit each year will increase from 10 to 65 and Pennsylvania’s climate will resemble what is found now in northern Alabama.

“Pennsylvania has not done enough to reduce emissions and support renewable energy sources,” said Mr. Najjar, adding that even if emissions are reduced by 80 percent, Pennsylvania likely will see summer temperatures rise by 5 degrees Fahrenheit, giving it a climate resembling that of southern Kentucky today.

City and county officials must start now to adapt policies and programs to climate-altered and expanding public health needs, said Karen Hacker, Allegheny County Health Department director.

“Infectious diseases, ticks, mosquitoes will all increase as the climate warms, as will severity and incidence of asthma, water problems and severe weather,” Dr. Hacker said. “The increases will likely be incremental, but the impacts will collectively be bigger.”

Leonard Bielory, a professor at Rutgers University where he is studying the impact of a warming climate on allergies, said globally longer pollination seasons are expected to increase the duration of exposure and also the number of individuals who develop sensitivity to it.

“Ragweed is responding to climate change on a continental basis, so we’re seeing earlier and later pollen seasons and it moves northward with warmer climate,” he said. “By 2020, we expect to see pollen increase by 20 percent in Pennsylvania, and by 2050 sensitivity to allergens could double from what it is now.”

Dr. Bielory said research shows climate change is also likely to cause an increase in dust mites, stinging insects and cockroaches. The production of poison ivy oil, which causes the itchy skin rash, will increase as carbon dioxide levels rise, weed growth will be stimulated and peanut allergies, which have doubled in each of the last several decades, will continue to increase.

Lyme disease, the most prevalent vector-borne disease in the U.S. with 30,000 diagnosed and perhaps nine times more undiagnosed cases, also is likely to increase among humans as the geographic range of the tick that causes it continues to expand, according to Dustin Brisson, an associate professor of biology at the University of Pennsylvania, whose research involves evolutionary biology, molecular genetics and microbial ecology.

Peter Adams, a professor of civil and environmental engineering and engineering and public policy at Carnegie Mellon University, said warmer air temperatures combined with expected higher humidity “makes the atmosphere more able to do chemistry and produce compounds that could impact human health.”

One of those compounds likely to increase is ground-level ozone, the primary component of unhealthy smog. Methane emissions from increased shale gas drilling, along with nitrogen oxides and volatile organic compound emissions from drilling operations and increased truck traffic, also could rise.

“Depending on how tightly those [shale gas drilling] operations are controlled,” Mr. Adams said, “there could be significant health impacts on Pittsburgh and Philadelphia and even more significantly in the center of the state.”

Clifford Mitchell, director of the Maryland Department of Health and Mental Hygiene, said that mitigation policies are important and the public needs to get involved to force emissions reductions, but health officials need to plan now for how a changing climate will impact local populations and communities.

“We need to help people adapt,” Dr. Mitchell said. “We’re going to be doing damage control and we need to figure out how to do that systematically.”

It also partially explains why there have been more bears walking through the backyard this summer, since they love to munch on the urushiol soaked leaves, the name for the oil or sap that lives on the skin of poison ivy and is such a pain for 85 percent of people.

An increase in carbon dioxide encourages plant growth like some kind of super fertilizer. And for some yet uncertain reason, poison ivy is proving especially greedy when it comes to CO2, sucking it down and spreading through fields and strangling trees at a record pace.

According to field studies by the Department of Agriculture, as long as CO2 levels keep rising, poison ivy will keep spreading, in some places virulently. It’s not just the number of plants that are growing, but also the potency of its poison. Global warming is literally changing the chemistry of the poison ivy; experts believe it has doubled in strength since the 1960s.

Poison ivy is not the only plant being impacted by global warming. Other studies, one by the biology department at Southwestern University in 2010, shows how an increase in CO2 increases photosynthesis in plants and encourages some to grow 30 to 40 percent faster. This is not necessarily a good thing. Even as they are growing faster, nitrogen levels in the plants are decreasing—as are othere important minerals including calcium, magnesium and phosphorous—which makes them drastically less nutritious for the herbivores (and man) that depend on them.

So, this is our future. Dirtier air and faster growing, evil-intended plants. I’m guessing next we’ll see news stories confirming that cockroaches and rats somehow thrive on increases in CO2. (Somewhat to the contrary, if you believe that superstorms, like Sandy, are encouraged by global warming they are proving to be hard on rat populations. The rat population in NYC went down post-Sandy, due to drowning.)

Be careful out there! Poison ivy’s ill effects aren’t only gained from brushing up against it in the woods. If its vines are burned or even churned up by weed whacker or lawn mower, the poisonous oil can become airborne and impact susceptible lungs.

What can you do about this advance, if you’re among the majority badly infected by poison ivy, the itchy, pimply blisters of which can last for several days?

First and foremost, learn to identify the plant. And then stay far away from it. Truth is, if you show the plant to most they mistake it for something innocuous, even marijuana.

Some Forest Service employees spray antiperspirant deodorant on exposed skin because the aluminum chlorohydrate may help prevent the oil from penetrating skin. (A human form of geo-engineering!)

At our house, where others are very susceptible, we keep a big, red bottle of Tecnu soap next to the sink all summer long and at the merest inkling of a brush-up there’s a rush for cold water and soap. (If you think you’ve made contact, move fast. The oil on the leaves, which is the ‘poison’ in poison ivy, often doesn’t sink into skin for about 15 minutes.) Jumping in a cold pond or pool is a possible instant remedy; Calamine lotion and ice can work after the fact.

It’s not like the measles or chicken pox. Apparently once you’ve had an allergic reaction to poison ivy you become even more at risk.

Climate change means mutant poison ivy

Climate change means mutant poison ivy – Back in college, I developed an oozing poison ivy rash all over my neck and arms and had to go on steroids — just because I inadvertently grazed the clothes of a friend who had gone tromping through the woods earlier that day. What’s worse, it happened right before the Dalai Lama visited my school. While my classmates were leaning forward in their folding chairs to capture his every syllable, I was shifting in my seat, clutching a bottle of calamine lotion, and desperately trying to look calm while the Lama talked about peace of mind — something I only know from reading the transcript. It’s hard to listen while your skin is on fire.

So yeah, I’m pretty allergic to poison ivy. But a lot of people are — 80 percent of the population reacts to the vine with welts and maddeningly itchy rashes. So the fact that poison ivy plants are getting bigger and more poisonous due to climate change isn’t exactly welcome news. But that’s precisely what’s happening; scientific research indicates that with higher levels of carbon dioxide in the atmosphere, the poison ivy plant grows larger, and its “oil” (a.k.a. the awful poisonous stuff) becomes more potent.

Fortunately, someone’s already thinking about how we could do a better job getting rid of the plant. (Rabbits and deer might miss it — they’re immune to the ivy’s poison, so it makes a nice leafy lunch for them — but consequences to the overall ecosystem would be minor, experts say.) Last week a group of horticulturists, scientists, and nurses convened in Philadelphia for the first conference devoted exclusively to the nettlesome vine. Ivy eradication specialist Umar Mycka, who also works at the Philadelphia zoo, organized the small, four-day gathering. One of his goals was to swap itching remedies and removal strategies with other poison ivy experts.

“If you want to deal with a problem, you have to know what size problem you’re dealing with,” Mycka says. “These plants are so powerful to start with, it doesn’t take much of a touch from carbon to make it much worse.”

That’s exactly what scientists found when they planted poison ivy in an experimental forest at Duke University, piping in carbon dioxide to artificially raise the concentration of CO2 in the atmosphere to the levels it’s expected to be by about 2050. The result, published in 2006: like other plants subjected to a high-CO2 environment, the poison ivy plants grew 150 percent bigger, with 153 percent higher concentrations of their oil, called urushiol.

Lewis Ziska, a plant physiologist at the U.S. Department of Agriculture who co-authored the study, estimates that poison ivy plants are already growing 50 to 60 percent larger than they did 100 years ago. He told me that warmer temperatures are probably also pushing poison ivy-growing zones northward (again, as with many other plants), and urbanization is creating conditions amenable to the wily plant, which thrives in semi-developed areas with more sunlight.

“Think of heat islands or cities as climate change in miniature,” Ziska says. “There are higher C02 concentrations, higher temperatures. There’s a fragmentation of ecosystems. All of those factors allow poison ivy to enter an environment that it may not have been in before.”

At the Philadelphia conference, attendees had a chance to see poison ivy’s monstrous proportions firsthand. Mycka led them to a public park near the center of the city, where a large vine had been growing up a tree. Its weight after removal: 506 pounds. And climate change is going to make it worse? I can already feel my skin burning.